Floating dry-dock



G. C. ENGSTRAND. FLOATING DRY DOCK. APPLlCATlON men 050. 29. 1920.

Patented Apr. 26, 1921.

UNITED STATES PATENT OFFICE.

FLOATING DRY-DOCK.

Specification of Letters Patent.

Patented Apr. 26, 1921.

Application filed December 29, 1920. Serial No. 433,927.

To all whom it may concern:

Be it known that I, GUNNAR C. ENG- STRAND, a subject of the King of Sweden, residing at Brooklyn in the county of Kings and State or New York, have invented certain new and useful Improvements in Floating Dry-Docks, of which the following is a specification.

My invention provides a composite plank supporting framing for structures of quadrilateral section like dry dock Pontoons and wings.

Usually the construction of such structures involves heavy corner logs, to which the plank supporting frame members are dovetailed.

My invention provides for flanged steel members to support the planking or two opposite sides of the quadrilateral section and wooden members to support the planking of the two remaining sides of the section.

The ends of the steel members are also provided with flanged corner brackets which brackets are bolted to the wooden frame members as well as to that part of the planking which spans the brackets, thus insuring a rigid corner.

My invention has for another object to provide a composite framing which is readily assembled.

My invention provides a series of parallel wooden struts the ends of which are clamped between double steel frame members, and the frame thus formed is properly braced by steel links and tie rods.

In the drawing:

Figure 1 shows half a cross section of the floating dry dock.

Figs. 2 and 3 show thedetail of construction on an enlarged scale.

Referring to the drawing in which like reference characters designate corresponding parts, 1 represents the floating dry dock which comprises a pontoon part 2, with a side wall or wing 3 at each end.

The framing of the pontoon 2 comprises double flanged bottom and deck stringers 4. which clamp the ends of a series of wooden struts or uprights 5 and the stringers 1 are provided with corner brackets 6 between which flanged corner brackets the ends of the wooden side uprights 7 are clamped by means of bolts 8.

The corner planks 9 of the side planking are bolted to the corner brackets 6 by means of carriage bolts, and the remaining side planking is bolted to the wooden uprights 7.

The deck and bottom planking 10 is bolted to the double flanged stringers 4, which stringers at the bulkheads are provided with pin connections 11 around which the steel links 12 pass.

Tie rods 13 are provided to take the reversed truss stresses due mainly to the weight of the wings, which are located at the ends of the truss.

The center bulkhead is shown double with a space filled with concrete to insure watertightness.

The iraming of the wing 3 comprises double flanged uprights 1 1 which clamp the ends of a series of horizontal wooden struts 15 and the uprights 14 are provided with flanged corner brackets 16, between which corner brackets the ends of the wooden deck and bottom beams 17 are clamped by means of bolts 18.

The corner planks 19 of the wings are bolted to the corner brackets 16 by means of carriage bolts.

The side planking 20 is bolted to the double flanged uprights 1 1, which uprights are provided with connections for tie rods 21.

Bolts 22 serve the double purpose of securing the corner wing bottom plank and the corner pontoon deck plank 10' to their respective frame members, and also to secure the wing 3 to the pontoons 2.

The procedure of construction is as follows The double bottom pontoon stringers 1 are first located and the lower ends of the series of struts or uprights 5 are clamped between them.

The bulkheads are put up and the double deck stringers 1 are put in place on top of the bulkheads and the upper ends of the series of struts or uprights 5 are clamped between them.

The steel links 12 are put in place and the pin connections 11 are inserted.

The tie rods 13 are also put in position.

The wooden frame members or side uprights 7 are clamped in place between the corner brackets 6 and the corner planks 9 are bolted to the brackets.

The remaining side planking is bolted to the wooden side uprights 7 and the pontoon deck and bottom planking 10 is bolted to the double stringers 4 and the pontoon section is finished.

The construction of the Wings 3 proceeds in a similar manner and the dry dock 1 is thus completed without taking recourse to dificult framing and dovetailing.

I do not wish to be understood to limit myself to the construction of floating dry docks, as other floating structures like pontoons, barges,etc., can be readily built after the same method.

I claim:

1. In a floating structure, planking, quadrilatera'l frames comprising double flanged members to support the planking of two opposite sides of the quadrilateral section and single members to support the planking of the remaining-sides of the section, each end of the single members being clamped between the double flanged members.

2. In a floating structure, planking, quadrilateral frames comprising double flanged members to support the planking of two opposite sides of the quadrilateral section and single members to support the planking of the remaining sides of the section, flanged brackets secured to the double flanged members, each end of the single members being clamped between the flanged corner brackets, and planking bolted to thedouble flanged members and to ,the flanged corner brackets.

33. In a floating structure, wooden planking, frames supporting the planking, said frames comprising a series or" parallel'struts, each end of which is clamped between double flanged frame members, and diagonal frame members attached to the double flanged members.

GUNNAR C. ENGSTRAND.

I'Vitnesses:

FRANK NICHOLS, FREDERICK I/V. QUIDAs. 

